Classifier



7; 1943.l l. TAYLoR A cLAsSIFIER Original Fileddan. 21, 1939 4snee'ts-sheet 1 Sept. 7, 1943. c. L TAYLQR .cLAssIFIER Ori nal FiledJan. 21. 1939 4 sheets-sheet 2 A NORA/.frs

Sept. 7, 1943. y c. L ,frAYLoR cLAssIFIER Original Filed Jan. 21, 1959 4Sheets-Sheet 3 -72A 73 97a v/NVENTO/. CL4/FENCE L. 7A YZOE A TroR/vfrs nC. l.. TAYLOR sept. 7, 1943.

CLASSIFIER originali-11m Jan. 21, 1939 4 .sheets-.sheet 4 Patented Sept.7, 1943 aszasse CLASSIFIER Clarence L. TaylonYoungstown, Ohio, assignorto The Aetna-Standard Engineering Company, Youngstown, Ohio, acorporation of Ohio Original application January 21, 1939, Serial No. I

252,152. Divided and this application June 12, 1942, Serial No. 446,683

9 Claims.

This invention relates to a piling apparatus particularly adapted foruse in classifiers for gauging sheet materials and separating the gaugedsheets in accordance with variations in their thickness.` The inventionis described I. herein in its application to the production of tin platebut it is to be understood that the invention may be used in conjunctionwith other materials and that the description of the preferred form ofmy invention contained herein is given only by way of example. Thisapplication is a division of my application Serial No. 252,152, filedJanuary 21, 1939, Patent No. 2,291,261, July 28, 1942. The presentapplication contains claims .directed more particularly to the mechanismwhereby the sheets are accurately piled, without being damaged. Thearrangement oi magnets disclosed herein is claimed more broadly in mycopending application aforesaid, while structural features of theclassifiers are claimed in 'my copending application Serial No. 446,684flied of even date herewith.

Users of tin plate require that the thickness of the sheets furnishedthem be maintained within very close tolerances. Sheets that are toothick or too thin are likely to result in defective products or in thebreaking of the dies of the can making machinery. Therefore it isessential for manufacturers of tin plate accurately to classify thesheets in accordance with their thickness to insure delivery of sheetsof proper gauge totheir customer. For the sake of economy it isessential that the classifier apparatus operate of the classifier; andFigure 7 is an end elevation of the delivery end.

My apparatus is particularly adapted for use in conjunction with moderntin mills of the continuous type in which the metal is delivered afterthe rolling operation in the form of bright annealed eleetrolyticallycleaned coils of tin plate which require only tobe shearcd to the properlength and classified according to thickness before being shipped to thecustomer. Ordinarily there are slight, but important, variations in thethickness of the rolled strip, and it is because of these variationsthat the sheets must be classified and sheets of the desired thicknessseparated from those sheets of greater or lesser thickness. Theclassified sheets must be piled accurately and rapidly and must not bedamaged by the piling operation.

In Figures 1 and la I have diagrammatically illustrated a preferredlayout of my apparatus for shearing and classifying'strips of tin plateformed ona continuous mill. As shown in the drawings', a strip S of tinplate is fed from a coil C by a suitable uncoiling device through anedge trimmer indicated at 20. This is driven by an electric motor 2iwhich exerts sufllcient tension to unwind the strip from the coil. Be-

at highspeed without damaging the sheets and that the classifieraccurately pile or stack the sheets so that they can be handledconveniently.

Accordingly it is a general object of my present invention to provide anapparatus, particularly suited for use in a classifier, but also adaptedfor other uses, which is adapted to operate at high -speeds and to pilesheets accurately without damaging them.

Various other objects oi'. my invention will become apparent from thefollowing Vdescription of a preferred embodiment thereof, referencebeing made to the accompanying drawings. The essential characteristicsare` summarized in the claims.

In the drawings, Figures 1 and 1a diagrammatically illustrate aclassifier embodying piling apparatus made in accordance with myinvention showing the arrangement of the associated equipment;I Figure 2is a diagram showing .a preferred wiring arrangement for the electricalcontrols for the classifier and associated equiplment:'liigure 3 is aside elevation of the' classifier. some of the parts being omitted forconvenience of illustration; Figure 4 is a plan view of the feed end ofthe classifier; Figure 5 is a vertical section taken along line 5-5 ofFigure ,3; `Figure 6 is a plan view of the delivery end yond the edgetrimmer the strip is allowed to sag, as shown. to give a little slack inthe strip to take care of fluctuations in the speed of the followingapparatus, and is then passed through felt pads indicated at 22 whichfunction to remove dust and chips from the strip. Then the strip isautomatically gauged by a continuous gauging device 23.

From the gauge 23. the strip passes through a V roller leveler indicateddiagrammatically at 24. pinch rolls 25, and thence to the rotary shear26, the roller leveler, pinch rolls and shear being driven by a singlemotor 21. 'Change speed gears (not shown) are incorporated in the driveof the shear 2G so that the shear can be adjusted to cut differentlengths of sheets. The construction and arrangement of the gears, shearand associated mechanism are well knownin the art and form no part ofthe present invention and accordingly will not be described furtherherein.

From the shear 26, the sheets are delivered t0 the'classier proper whichis illustrated somewhat diagrammatically in Figure la. The details ofthe classifier will be described later, but for the present it will besufficient to state that the sheets are deposited on a conveyor belt 3U1,000 ft. per minute, it being desirable to space the ends of successivesheets a distance of approxim `tely 1 ft. Obviously the difference inspeed b tween the belt 30 and the strip necessary to accomplish thedesired spacing depends upon the length of'sheets being cut by theshear.

, After leaving the belt 30, the sheets if they are of proper gauge passover the flipper or defiector 32 which is pivotally mounted on a shaft33 and arranged to be raised or lowered by a solenoid 34 controlled bythe continuous gauge 23. The gauge 23 and the control circuit foroperating the solenoid 34 do not per se form a part of this invention, asuitable type of gauge being disclosed in United States Patent No.2,007,840. For the purposes of this specification, it will suffice tosay that in the present instance, the circuit is arranged so that thesolenoid 34 is energized to raise the flipper 32 and thus deflect thesheets downwardly beneath the ipper in the event that the thickness ofthe strip material varies from a predetermined standard an amount inexcess of the established tolerances, while so long as sheets of properthickness are being delivered the solenoid will not be energized, theflipper will remain in substantially horizontal position as shown infull lines in Figure 3, and the' sheets will pass over the flipper andbe delivered to the belt 35. The sheets upon delivery to the belt 35 maybe traveling at very high speeds on the order of 1,000 ft. per minute.Necessarily the speed must be reduced gradually in order to make itpossible to accurately stack the sheets without damaging their edges.Therefore the belt 35 is driven by the motor 36 at a reduced speed, say820 ft. per minute, if the belt 30 has been operating at 1,000 ft. perminute. From the belt 35 the sheets pass the belt 31 where the speed isfurther reduced. In the example given, this belt may be driven at thespeed of the shear, say 600 ft. per minute, the drive being accomplishedby the motor 33. Thus fon belt 31, the sheets will be closely spaced.

From the belt 31, the sheets are discharged onto the final belt 39disposed at a slightly lower level than belt 31 and driven atconsiderably slower speed. In the example given the speed of the belt 33may be about 240 ft. per minute. Because of this very Aconsiderablereduction in speed, it will be evident that the sheets will bedischarged into belt 39 in overlapping relationship. That is to say,they will be shingled as diagrammatically indicated in Figure 1a of thedrawings.

From the belt 39 the sheets are passed between rolls 4U and 4| and overroll 42, all of which are driven in synchronism with the belt by themotor 43, and discharged onto the elevating platform 44. Theconstruction and arrangement of the discharge mechanism and guides 45,46 and 41 associated with the platform form an important part of myinvention and will be described in detail below. The platform 44 isarranged to be raised or lowered by a suitable elevating mechanismindicated in general at 48, and in operation the platform is graduallylowered as sheets are discharged thereon.

In the event that a sheet of incorrect thickness is delivered onto belt30, then by the control mechanism briefly described above the solenoid34 will be energized to raise the flipper 32 to the full line positionof Figure la of the drawings as the sheet approaches the solenoid. Thusthey sheet will be deflected downwardly to the belt disposed beneathbelt 35. Sheets of incorrect gauge are then carried along belts 31 and33' similar to f various motors operating at correct relative belts 31and 33 previously described: the belts being driven by motors 33', 33'and 43'. The discharge mechanism includes rollers 4|'. 42' and elevatingplatform 44' with associated guides 45', 46' and 41', the platform beingraised and lowered by the elevating mechanism 48. The sheets are heldagainst the various belts by magnets M and M'. These insure accuratepositioning of the sheets and prevent the sheets from planing throughthe air, all as described in greater detail in my parent applicationaforesaid.

Preferably the apparatus should be readily adaptable for use inclassifying sheets of tin plate of diierent lengths, widths and gauges.Thus the controls must be flexible so that the speeds of the variouselements may be easily varied in order to obtain proper operatingconditions. So far as I am aware the best operating speeds for eachparticular size of sheet can only be determined experimentally.Therefore a control system by means of which various speeds can beobtained readily without stopping the machine is essential to eflicientoperation of the machine. To attain this end, I preferably provideindividual motor drives for the belts, the shear and the edge trimmer asdescribed above and provide each motor with an individual speed controlso that its speed can be varied independently of the speed4 of everyother motor. Further all of the motors may be stopped and startedsimultaneously and the speed of all of the motors may be variedsimultaneously by means of a Ward-Leonard control system.

The wiring arrangement for this control is shown diagrammatically inFigure 2 in which the Ward-Leonard, or variable voltage, generator isindicated at 50. The field current of the generator is controlled by therheostat 5i which thus varies the output of the generator. The currentgenerated is delivered through conductors 52 and 53 to armatures of themotors 2|, 21, 3i, 36, 36', 38, 38', 43 and 43' which are all connectedin parallel with the result that if the rheostat is adjusted, forexample, to increase the field cur- I rent of the generator the speed ofall of the motors will be increased, and conversely if the generatorfield is weakened the speed of all of the motors will be reduced.Individual control to separately l adjust the relative speeds of themotors is attained by the motor eld rheostate R-Z I, R-21, and R-3I,R-3B, R--36, lit-38, R-33', ft- 43 and R-43', respectively, which arecarried by the frame of the classifier. Weakening the shunt fields ofthe motors by means of the rheostats increases their speed, andstrengthening the fields reduces their speed. By this arrangement veryflexible control is obtained. The speeds of all of the motors can beadjusted to best advantage by the various field rheostats and the entiremachine can be stopped or started or varied in speed during operation byrheostat 5i without changlng the individual setting of the fieldrheostats. By this control scheme not only can the machine be operatedto best advantage but also no time is wasted when the machine must bestopped, for instance to supply a new coil of material, as the entireapparatus can be stopped by the rheostat 5I and immediately startedagain with all of the speeds.

Referring to Figures 3 to '1, inclusive, it will be seen that themechanism is supported on a suitable oor or base by frame members 60, 6Iand 62 and suitable vertical frame members 53, 84 and 65 which areduplicated on opposite sides of the machine. The motors and associateddriving mechanism are supported by a. girder or beam 66 which extendslongitudinally o! the machine along one side thereof and which issupported' by the vertial members 63, 64 and 66. It will be noted thatthe girder 66 is a box construction and as shown particularly in Figure6 supports all of the driving mechanism and `the belts, except for thesupports furnished immediately adjacent the upright members 63, 64 and65. Beneath the girder 86, longitudinally extending members 61 and 66(Figures 3 and 5) are provided which function to support the eldrheostats Rf-3I, etc. for controlling the speeds of the individualmotors, the backs of these rheostats being shown in Figure 3. By thisconstruction, the driving mechanism and controls are all concentratedalong one side of the machine, making them readily accessible to theoperators, while the opposite side of the machine is open except lin theimmediate vicinity of the vertical supports 63, 64 and 65. Thus theconveyor belts are readily accessible and can be replaced easily withouttearing down the machine and because of its open construction theoperation of the machine can be clearly observed so that any necessaryadjustments can be made.

As previously pointed out, the sheared sheets are discharged from theshear 26 onto the conveyor belts 30 which operate on rollers or pulleys69 and 69a, the pulleys 69 being driven by a shaft 10 while thepulleysl69a are idlers. The shaft 10 is supported by bearings 1| and 1|amounted in bracket 16 at opposite sides of the machine, and at its endis provided with a sprocket 'l2 so that it may be driven by the motor 3|through the chain 13.

In order to provide means whereby the level oi' the belts 30 may beadjusted to accommodate the belts to variations in the level of the passline through the shear, the bearings for the pulleys 69a are supportedby suitable brackets 14 on longitudinally extending rods 15, which arein turn mounted on the transversely extending bracket 16 supported bybearings 18 in the girder 66 (see Figures 4 and 5). The end portion ofthe bracket 16 is concentric with the shaft 10 and the bearings 1| aredisposed within the end of the bracket 16. Thus the bracket and arms maybe rotated about the axis of shaft 10 to raise and lower the belts 30without changing the distance between the pulleys 69a and the pulleys69. The belts are supported at the desired level, either at or slightlybelow the pass line of the shear, by rods 80 pivotally mounted at theirlower ends. to a suitable frame member or support 8| as at 82. At theirupper ends, the rods are pivotally connected as at 83 to a transverselyextending bar 84 extending within the belts and channeled to receive therods 15, the bar being cut away to receive the rods and being providedwith cover plates. 85 secured in clamping engagement with the rods 15.It will be evident that by loosening the screws 86. the bar 84 can beslid along the bars 15 in either direction to raise or lower the pulleys69a. By this means the belts 30 can be adjusted vertically to asuiiicient extent to insure that the sheets will be properly deliveredby the shear. Y

From the belts 30 the individual sheets pass either above or below theiiipper or deilector 32,

depending upon whether the sheets are of standard "thickness or not. Thedeiector 32 is mounted upon a shaft 33 which is supported for rotationby suitable bearings in the girder 66 and `3 in the bracket 89, mountedupon the frame member 63. The defiector 32 is rotated from one positionto another by the solenoid 34 through a connectingrod and the shaft 33,the solenoid being actuated in response to changes in strip thickness asdescribed above. As long as strip of standard thickness is being fedthrough the gauge, the deflector 32 remains in its lower position asshown in Figure 3 of the drawings, but if the thickness of the Stripvaries either above or below the standard thickness by an amountexceeding the established tolerances the deflector will be raised todeflect the sheets downwardly onto the lower series of belts. Assumingthat the sheets delivered to the belts 30 are within the establishedtolerances, then the sheets will be delivered over i deflector'32 to thebelts 35, a roller 9|a. being interposed between the deflector and thebelts to reduce the friction on the sheets in traveling between thesuccessive belts.

The belts 35 are carried by pulleys 93 and 94, the arrangement beinggenerally similar to the lsupporting mechanism described in conjunctionwith the belts 30; i. e., the'pulleys 93 are driven by a `shaft whichextends through and is supported by a bracket 96, similar to the bracket16, and mounted in suitable bearings carried by the girder 66. The endof the shaft 95 is provided with a sprocket 91 so that the shaft may bedriven through the chain 91a. by vmotor 36. The idler pulleys 94 aresupported by suitable bearings carried by brackets 98 mounted on rods 99which are supported by the transversely extending bracket or arm 96.

To provide for vertical adjustment of the belts 35, a bracket '|00pivotally mounted on the girder 66 by bar |00a and supporting a bar |0|generally similar to bar 84, is employed. The rods 99 and pulleys 92 maybe raised and lowered by rotating the bracket |00 about its pivot andsliding the bar |0| along the rods. Only a small amount of adjustment isprovided for the level of the belt 35 as no great range of adjustment isrequired.

The tension on the belts 35 can be adjusted by moving the brackets 98along the rods 99 by means of nuts |02 in threaded engagement with therods. A similar scheme is employed for acljustment of the tension on thebelts 30.

As previously noted, only sheets of standard gauge are carried by belts35, the velocity of the sheets as they are delivered to belts 35 issubstantially the velocity of the belts 30, for example about 1,000 ft.per minute, and the slowing down of the sheets so that they can bestacked accurately and without damage is started on the belts 35. Thusthe belts 35 may be operated at a speed of about 800 ft. per minute.From the belts 35 the sheets are delivered to belts 31 where thevelocity is further reduced, preferably to such an extent that thesheets are deposited on the belt with very little space between thesheets. The belts 31 are carried by pulleys |03 and |04 and supported bya transversely extending bracket |05, rods |06 vand adjusting bracket|01, all substantially identical with the mechanism described forsupporting the belts 35 The driven pulleys |04 are keyed to shaft |06awhich is driven by motor 38 through chain |08 and sprocket |09.

The belts 31 deliver the sheetsto belts 39 which are driven by motor 43through mechanism simi- -lar to that previously described at a velocityle s s less than the peripheral speed of'the shear. The belt ispretcrank arm 9| keyed to.

v31, so that the sheets are deposited thereon in overlapping or shingledrelationship as indicated in Figure 1a and carried thereby in thisshingle arrangement to the piler mechanism at the delivery end of themachine. The pulleys for supporting the belts 39 and the associatedbrackets are similar in all material respects to the mechanism describedpreviously with respect to belts 35 and 31 except that two brackets H0,similar to the 4brackets |00 and |01 previously described, are employedin conjunction with two bars for supporting the longitudinally extendingbars H2, because the belts 39 are considerably longer than the Vbelts 35and 31, the 15 additional length being necessary to convey .the sheetsbeyond the piler mechanism for the olfgauge sheets which have beendeflected by the flipper 32.

The velocity of the belts 39 may be, for example, about half theperipheral speed of the' shear, thus reducing the speed of the sheets tosuch an extent that they can be piled accurately without damaging thesheets. The piling appa ratus is illustrated particularly in Figures 3,6 and '7. As illustrated, the sheets in their shingled arrangement onbelts 39 are passed between the concave and convex fabric rolls 40 and4|, the roll being driven by a chain ||1 and suitable j sprockets atsubstantially the speed of the belt 39. The rolls 4 0 and 4| areconstructed of cotton or other suitable material 'much in the manner ofbufiing wheels and are given concave and convex contours so that thesheets passing between the rolls are bent in such a manner that theirupper surfaces are concave, thus increasing the rigidity of the sheetsand preventing their vforward ends from bending downwardly until therear portions of the sheets have been released, from the rolls. Theoverlapping of the sheets ini the pinch rolls also assists in the properdelivery i thereof, for the trailing edge of each sheet is held down bya following sheet, resulting in the projection of the sheets from thepinch rolls a substantially horizontal plane. 4"

To provide adequate pressure between the rolls 40 and 4|, the upper roll40 is supported by bearings mounted on brackets |20 carried by arotatably mounted shaft |2|. The adjustable springs |22 and |23, mountedon the main frame and engaging above and below lever |24 rigidlyconnected to shaft |2| maintain the-roll 40 in engagement with roll 4|with the desired pressure.

The sheets as they are discharged immediately assume their previous flatcondition and are projected forwardly and downwardly onto a suitableplatform 44 which may be elevated by the elevating mechanism 48 to aposition so that the top of the pile of sheets is Within the areaenclosed by the side guides 41 and the members 45. The position of theelevator may be manually controlled by any ordinary means, the practicebeing to gradually lower the platform as sheets are deposited thereon.

The stops or guides are carried by an arm |28 pivotally and slidablymounted on rod |29, and the end of the arm engages the underside of rod|30 as indicated at |3|. Thus the arm can be slid along to vary theposition of the stop for different size `sheets and also can be swungupwardly and out of the way as indicated in dotted lines in Figure '1.

The side guides 41 project forwardly from and, are carried -by guideplates 46 (see Figures 3 and 1). The plates 43 and guides 41 may bemoved toward or away from eachother along a supporting rod |3|a byscrews |32 extending transversely of the end of the main frame member,the sheets being guided laterally by the side guides and being projectedagainst the end guide or stop member 45 with the result that a straightpile of sheets is formed.-

To insure that ach sheet will be projected with suillcient velocity fromthe pinch rolls 40 and 4| to cause it to abut the end guide 45 and alsoto straighten out any sheets that may be slightly deflected in theirtravel through the machine, I preferably employ a roller 42 of polishedsteel driven by sprockets |34 and |35 and chain |38 at substantially thesame velocity as the belt 39.

The sheets dropping from the grip of the pinchl I rolls are given aslight forward impetus by the roller which is suiilcient to straightenout the sheets and give them sufilcient velocity to cause them to bepiled in a straight pile with their forward edges abutting thestop 45.

As previously described in connection with Figure/1a, the flipper 32 israised by the solenoid 34 whenever a sheet of incorrect gauge isapproaching the flipper so that any such sheets will be deflecteddownwardly under the lower series of belts as', 31' and 39' and finallydischarged onto the elevating platform 48'. The arrangement of the beltsand their driving mechanism is in all material respects the same as thearrangement of the upper series of belts described in detallabove, andthe description will not be repeated here. Corresponding parts in thelower series of belts are marked with reference characters correspondingto those applied to the upper series.

By reason of its various novel features, my apparatus can accuratelyclassify sheet material at very high speed. Because of my convenientcontrol system, the various instrumentalities making up my apparatus canbe readily adjusted to operate at the most eillcient speeds, and alsoall of the driving motors can be simultaneously started and stopped andtheir speed adjusted by a single control. The piling apparatus can beadjusted readily to accommodate different sizes of sheets, and for allsizes within the range of adjustment the sheets are accurately anduniformly piled without damage thereto. The

0 shingling of the sheets makes it possible to slow them down so thatthey can be piled accurately without damage and also assures properdelivery of the sheets by the pinch rolls. The flexible speed controlarrangement makes possible the proper adjustment of the speeds of thevarious belts and rolls to obtain the desired amount 'of overlapping ofthe sheets and the proper discharge speed to insure accurate piling.

In the foregoing specification I have described in detail a preferredform of my invention. Various changes and modifications can be madetherein without departing from the spirit and scope of my invention, andit is therefore to be understood that my patent is not limited to thepreferred form described herein or in any manner other than by the scopeof the-appended claims.

I claim:

1. In an apparatus for classifying thin sheet material, a series ofconveyor belts for conveying the sheets through the apparatus, saidbelts operating at progressively slower speeds and the receiving end'ofone of the belts being disposed below the discharge end of theimmediately preceding belt whereby said sheets are deposited on saidbelt in overlapping relationship, means for regulating the speed of saidbelts, and means for 2,328,859 Apiling the material delivered by thelbelts com-A erally horizontal plane until released by said pinch prisinga. platform, a pair of pinch rolls comprising a concave roll and a.convex roll disposed one above the other and adapted to receive sheetsdelivered by said series of belts and to discharge said sheets` ontosaid platform, means for driving said pinch rolls, side guides and astop member for guiding said sheets onto said platform, a roll Y ing atprogressively slower speeds and the receiving end of one of the beltsbeing disposed below the discharge end of the immediately preceding beltwhereby said sheets arev deposited on said belt in overlapping"relationship, and means for piling the material delivered by the beltscomprising a platform, a pair of pinch rolls comprising a concave rolland a convex roll disposed one above the other and adapted to receivesheets delivered by said series of belts and to discharge said sheetsonto said platform, means for driving said pinch rolls, means forguiding said sheets onto said platform, a roll disposed adjacent thelower ofv said pinch rolls and adapted to engagev the trailing edges ofthe sheets as they are discharged from said pinch rolls` and means fordriving said roll.

3. In an apparatus for piling thin metal sheets, the combination of aconveying mecha- -nism including a series ofl belts for conveying sheetsthrough said apparatus, one of said belts lbeing adapted to dischargesheets onto another belt operated at a slower speed and disposed at alower level than the discharge end of said rst belt, whereby sheets aredeposited on said other belt in overlapping or shingled relationship,and 'means forvpiling said sheets comprising a pair of pinch rollsadapted to receive said sheets from said last named belt and to deliversaid 'sheets onto a platform, the lower of said pinch rolls having aconcaved surface and the upper' of'said pinch rolls having a convexsurface whereby sheets passing between said pinch rolls are bent into aconcave-convex form by saidpinch rolls and arexheld in such form in agenerally horizontal plane until released by said pinch rolls anddischarged onto said platform, and a driven roll disposed adjacent thelower of said pinch rolls and adapted to engage .the trailing edges ofthe sheets. f

4. In an apparatus for classifying and piling thin ferrous sheets, thecombination of aconveying mechanism including a series of belts forconveying sheets through said apparatus at high speed,"one of said beltsbeing adapted to dis-` charge sheets onto another' belt operated at aslower speed and disposed at a lower level than lthe discharge end ofsaid first belt, whereby sheets are deposited on said other belt inoverlapping or shingled relationship. magnets for holding said sheetsincontact with said belts, and means for piling said sheets comprising apair of resilient pinch rolls adapted to receive said sheets from saidlast named belt and to deliver said sheets onto a platform, the lower ofsaid pinch rolls having a concaved surface and the upper ofsaid pinchrolls having a convex surface whereby sheets passing between said pinchrolls are bent into a concavo-convex form by said pinch rolls and areheld formin agenrolls, a stop member for guiding saidsheets onto saidplatform, and a driven roll disposed adjacent the lower of said pinchrolls and adapted 'to engage the trailing edges of the sheets as theyare discharged from said pinch rolls to cause said sheets to squarelyengage said stop.

5. In an apparatus for piling thin metal sheets, the combination of aconveyor belt, means for depositing sheets on said belt in shingledrelationship, and means for piling said sheets comprising a pair ofresilient pinch rolls adapted to receive saidsheets from said' belt andto deliver said sheets onto a platform, the lower of said pinch rollshaving a concaved surface and the upper ofv said pinch rolls having aconvex surface whereby sheets passing between said pinch rolls are bentinto a concavo-convexform by said pinch rolls and are held in such formin a generally horizontal plane until released by said pinch rolls. astop memberfor guiding said sheets onto said g platform, and a drivenrou disposed adjacent the IIB lower of said pinch rolls and adapted toengage the trailing edges of thesheets as they are discharged from saidpinch rolls to cause said sheets to squarely engage said stop.

6. In an apparatus for piling sheet material, an elevating platform, apair of pinch rolls disposed one above the. other and adapted todischarge sheets onto said platform, means for driving said pinch rolls,a stop member for` guiding i said sheets onto said platform, a rolldisposed adjacent the lower of said pinch rolls and adaptl ed to engagethe trailing edges of the sheets as they are discharged from said pinchrolls to cause said sheets to squarely engage said stop, and means fordriving said. roll.

7. In an apparatus for piling sheet material, a platform, a pair ofpinch rolls disposed one above the other and adapted to discharge sheetsonto v said platform, means for feeding sheets tosaid pinch rolls inshingled relationship, means for driving said pinch rolls, a stop memberfor guiding said sheets onto said platform, a roll disposed J adjacentthe lower of said pinch rolls and adapted toengage the trailing edges ofthe sheets as they are discharged from said pinch rolls to cause saidsheets to squarely engage said stop, and means for driving said roll. 4

8. In an apparatus for piling sheet material, a platform, a pair ofpinch rollsdisposed o ne above the other and adapted to discharge sheetsonto said platform, one of said rolls being concave and the `otherconvex, means for feeding sheets to said pinch rolls, means for drivingsaid pinch rolls, a stop for guiding said sheets onto said platform, aroll disposed adjacent the lower or said pinch rolls and adapted toengage the trailing edges of the sheets as they are discharged from saidpinch rolls to cause said sheets to squarely engage said stop, and meansfor driving said roll.

9. In an. apparatus for piling sheet material, a platform-.a pair ofpinch rolls disposed one above the other and adapted to discharge sheetsonto said platform, one of said rolls being concave and the otherconvex, meam fordriving said pinch rolls, means for guiding said sheetsontosaid platform, a roll disposed adjacent the lower of said pinchrolls and adapted to engage the trail- 'ing edges of the sheets as theyare discharged

